According to CVS and Rite Aid’s suit, Pfizer’s Wyeth unit schemed with Teva, a generic manufacturer, to prevent other generic versions of Effexor XR from reaching store shelves for at least two years after its exclusive marketing rights to the drug expired in June 2008. The suit claims Wyeth accomplished this by obtaining fraudulent patents, engaging in fake litigation with Teva and other generic manufacturers, and scheming to prolong Teva’s generic exclusivity rights. As a result, the retailers claim they were overcharged.